Forest Co-op Marten Habitat Program
The Forest Co-op has supported a major initiative investigating habitat requirements and population ecology of the American marten. The Forest Co-op Marten Habitat Program has evaluated the sustainability of martens in forest landscapes near Ear Falls and Kapuskasing. This program also incorporates the results of a companion project, the Forest Co-op Marten Cores Project (2004-06). Goals of the program were to compare key ecological characteristics in mature, uncut forests with those in younger forests that have regenerated from forest harvesting 30-50 years previously and to make recommendations for management. A variety of approaches was used including radio-collaring and population viability analysis. Some of the conclusions vis-à-vis forestry guidelines from the final report delivered in February 2009 are:
• Marten populations are biologically sustainable (i.e. have positive carrying capacity) in landscapes dominated by regenerating forests 30-60 years of age. The available evidence is inconsistent with the source-sink hypothesis that forms the logical basis for Ontario Ministry of Natural Resources’ current marten habitat guidelines.
• There is a small, but significantly higher, risk to marten populations in landscapes dominated by regenerating forests than in landscapes dominated by mature forests, especially in areas with appreciable levels of fur-trapping. Marten populations grow faster and reach higher densities in mature forest, reducing the risk of decline due to environmental and demographic variability. Fur-trapping levels have critical bearing on the ratio of mature to regenerating stands needed to maintain viable populations of martens across a heterogeneous landscape.
• Comparisons between machine-logged and horse-logged stands suggest that forestry activities that maintain complex habitat structure, such as plentiful supplies of coarse woody debris, may be a useful means of improving habitat conditions for martens on managed landscapes.
• A key consideration for marten viability is the level of fur-trapping mortality. There is an urgent need to formally link furbearer management policy with forest management policy in Ontario. Both need to be better integrated to maintain desirable levels of population viability of key indicator species, such as marten. The population viability analysis model developed for this project could be used by managers to assess a variety of management options.
• Observed differences in marten population dynamics between landscapes dominated by regenerating versus mature forests are mirrored by significant differences in the abundance of coarse woody debris, predation efficiency, body condition, juvenile survival during dispersal, dispersal distance, and genetic structure. This evidence is consistent with the hypothesis that the fitness of martens depends to some degree on maturation stage of forests, but also to a considerable extent on forest structure, principally the supply of coarse woody debris.
This collaborative research program has generated student theses, many scientific papers and reports, and workshops to transfer the results. The integrated nature of the work and breadth of the results has inspired the principal researchers to write a book with details of the field results, model outcomes and policy recommendations.
Through leveraging, the combined investment of all parties in this initiative is in excess of $2.4 million.